The present invention relates to dyeing compositions containing dibenzenic nitro compounds comprising at least one cationic group Z chosen from quaternized aliphatic chains, aliphatic chains comprising at least one quaternized saturated ring and aliphatic chains comprising at least one quaternized unsaturated ring, to the use of such compositions as direct dyes in dyeing applications for keratin substances, in particular human keratin fibers and especially the hair, and to the direct dyeing processes employing such compositions.
In the field of hair dyeing, direct dyes are sought, i.e., dyes which, without supplying any oxidizing agent other than ambient air, are capable by themselves of temporarily modifying the natural shade of the hair. In this application, the dyes must satisfy a certain number of criteria, and in particular they must generate reproducible dyeing results with rich and varied shades, thus making it possible to obtain a wide range of colors capable of satisfying the formulator, it also being necessary for these dyeing results to be intense and fast with respect to washing, rubbing, light and perspiration.
The inventors have now just discovered, entirely surprisingly and unexpectedly, that dibenzenic nitro compounds of formula (I) defined below, comprising at least one cationic group Z chosen from quaternized aliphatic chains, aliphatic chains comprising at least one quaternized saturated ring and aliphatic chains comprising at least one quaternized unsaturated ring, are suitable for use as direct dyes for direct dyeing, and also that they make it possible to obtain dye compositions which lead to intense and varied colorations which have excellent properties of fastness with respect to the various treatments to which the keratin fibers may be subjected. Finally, these compounds have better solubility in the media conventionally used for dyeing keratin fibers and are found to be easy to synthesize.
These discoveries form the basis of the present invention.
A subject of the invention is thus the use, as direct dyes in, or for the manufacture of, dye compositions for keratin substances, and in particular for human keratin fibers such as the hair, of dibenzenic nitro compounds of formula (I) below, and the acid-addition salts thereof: 
in which:
B is a linker arm which represents a linear or branched alkyl chain preferably comprising from 1 to 14 carbon atoms, which can be interrupted with one or more groups Z and/or with one or more hetero atoms such as oxygen, sulphur or nitrogen atoms, and optionally substituted with one or more hydroxyl or C1-C6 alkoxy radicals, and which can bear one or more ketone functions;
R1, R2, R3, Rxe2x80x21, Rxe2x80x22 and Rxe2x80x23, which may be identical or different, represent one of the two valencies of a linker arm B; a hydrogen atom; a halogen atom; a group Z; a (C1-C6)alkylcarbonyl radical; an amino(C1-C6)alkylcarbonyl radical; an Nxe2x80x94Z-amino(C1-C6)alkylcarbonyl radical; an Nxe2x80x94(C1-C6)alkylamino-(C1-C6)-alkylcarbonyl radical; an N,N-di(C1-C6)alkylamino(C1-C6)alkylcarbonyl radical; an amino(C1-C6)alkylcarbonyl(C1-C6)alkyl radical; an Nxe2x80x94Z-amino(C1-C6)alkylcarbonyl(C1-C6)alkyl radical; an Nxe2x80x94(C1-C6)alkylamino-(C1-C6)alkylcarbonyl(C1-C6)alkyl radical; an N,N-di(C1-C6)alkylamino(C1-C6)-alkylcarbonyl(C1-C6)alkyl radical; a carboxyl radical; a (C1-C6)alkylcarboxyl radical; a C1-C6 alkylsulphonyl radical; an aminosulphonyl radical; an Nxe2x80x94Z-aminosulphonyl radical; an Nxe2x80x94(C1-C6)alkylaminosulphonyl radical; an N,N-di(C1-C6)alkylaminosulphonyl radical; a C1-C6 aminosulphonylalkyl radical; a C1-C6 Nxe2x80x94Z-aminosulphonylalkyl radical; an Nxe2x80x94(C1-C6)alkyl-aminosulphonyl(C1-C6)alkyl radical; an N,N-di(C1-C6)alkylaminosulphonyl(C1-C6)alkyl radical; a carbamyl radical; an Nxe2x80x94(C1-C6)alkylcarbamyl radical; an N,N-di(C1-C6)alkylcarbamyl radical; a carbamyl(C1-C6)alkyl radical; an Nxe2x80x94(C1-C6)alkylcarbamyl(C1-C6)alkyl radical; an N,N-di(C1-C6)alkylcarbamyl(C1-C6)alkyl radical; a C1-C6 alkyl radical; a C1-C6 monohydroxyalkyl radical; a C2-C6 polyhydroxyalkyl radical; a (C1-C6)alkoxy(C1-C6)alkyl radical; a C1-C6 trifluoroalkyl radical; a cyano radical; an unsubstituted or substituted amino radical, in which the substituents on the amine, which may be identical or different, have the same meanings as the variables R4, R5, Rxe2x80x24 and Rxe2x80x25 described below; an amino(C1-C6)alkyl radical in which the alkyl is unsubstituted or substituted with one or more hydroxyl radicals and in which the amine is substituted with one or two identical or different radicals chosen from C1-C6 alkyl, C1-C6 monohydroxyalkyl, C2-C6 polyhydroxyalkyl, (C1-C6)alkylcarbonyl, carbamyl, Nxe2x80x94(C1-C6)alkylcarbamyl or N,N-di(C1-C6)alkylcarbamyl, C1-C6 alkylsulphonyl, formyl, trifluoro(C1-C6)alkylcarbonyl, (C1-C6)alkylcarboxyl and thiocarbamyl radicals, or with a group Z; or a group OR6 or xe2x80x94SR6; R6 denotes one of the two valencies of a linker arm B; a hydrogen atom; a C1-C6 alkyl radical; a C1-C6 monohydroxyalkyl radical; a C2-C6 polyhydroxyalkyl radical; a group Z; a (C1-C6)alkoxy(C1-C6)alkyl radical; an aryl radical; a benzyl radical; a carboxy(C1-C6)alkyl radical; a (C1-C6)alkylcarboxy(C1-C6)alkyl radical; a cyano(C1-C6)alkyl radical; a carbamyl(C1-C6)alkyl radical; an Nxe2x80x94(C1-C6)alkylcarbamyl(C1-C6)alkyl radical; an N,N-di(C1-C6)alkylcarbamyl(C1-C6)alkyl radical; a C1-C6 trifluoroalkyl radical; a C1-C6 aminosulphonylalkyl radical; a C1-C6 Nxe2x80x94Z-aminosulphonylalkyl radical; an Nxe2x80x94(C1-C6)alkylaminosulphonyl(C1-C6)alkyl radical; an N,N-di(C1-C6)alkylaminosulphonyl(C1-C6)alkyl radical; a (C1-C6)alkylsulphinyl(C1-C6)alkyl radical; a (C1-C6)alkylsulphonyl(C1-C6)alkyl radical; a (C1-C6)alkylcarbonyl(C1-C6)alkyl radical; a C1-C6 aminoalkyl radical; a C1-C6 aminoalkyl radical in which the amine is substituted with one or two identical or different radicals chosen from C1-C6 alkyl, C1-C6 monohydroxyalkyl, C2-C6 polyhydroxyalkyl, (C1-C6)alkylcarbonyl, formyl, trifluoro-(C1-C6)alkylcarbonyl, (C1-C6)alkylcarboxyl, carbamyl, Nxe2x80x94(C1-C6)alkylcarbamyl, N,N-di-(C1-C6)alkylcarbamyl, thiocarbamyl and C1-C6 alkylsulphonyl radicals, or with a group Z;
R4, R5, Rxe2x80x24 and Rxe2x80x25, which may be identical or different, represent one of the two valencies of a linker arm B; a hydrogen atom; a group Z; a C1-C6 alkyl radical; a C1-C6 monohydroxyalkyl radical; a C2-C6 polyhydroxyalkyl radical; a (C1-C6)alkoxy(C1-C6)alkyl radical; an aryl radical; a benzyl radical; a cyano(C1-C6)alkyl radical; a carbamyl(C1-C6)alkyl radical; an Nxe2x80x94(C1-C6)alkylcarbamyl(C1-C6)alkyl radical; an N,N-di(C1-C6)alkylcarbamyl(C1-C6)alkyl radical; a thiocarbamyl(C1-C6)alkyl radical; a C1-C6 trifluoroalkyl radical; a C1-C6 sulphoalkyl radical; a (C1-C6)alkylcarboxy(C1-C6)alkyl radical; a (C1-C6)alkylsulphinyl(C1-C6)alkyl radical; a C1-C6 aminosulphonylalkyl radical; a C1-C6 Nxe2x80x94Z-aminosulphonylalkyl radical; an Nxe2x80x94(C1-C6)alkylaminosulphonyl(C1-C6)alkyl radical; an N,N-di(C1-C6)alkylaminosulphonyl(C1-C6)alkyl radical; a (C1-C6)alkylcarbonyl(C1-C6)alkyl radical; a C1-C6 aminoalkyl radical; a C1-C6 aminoalkyl radical in which the alkyl is unsubstituted or substituted with one or more hydroxyl radicals and in which the amine is substituted with one or two identical or different radicals chosen from alkyl, C1-C6 monohydroxyalkyl, C2-C6 polyhydroxyalkyl, (C1-C6)alkylcarbonyl, carbamyl, Nxe2x80x94(C1-C6)alkyl-carbamyl or N,N-di(C1-C6)alkylcarbamyl, C1-C6 alkylsulphonyl, formyl, trifluoro(C1-C6)alkylcarbonyl, (C1-C6)alkylcarboxyl and thiocarbamyl radicals, or with a group Z;
Z is chosen from the unsaturated cationic groups of formulae (II) and (III) below, and the saturated cationic groups of formula (IV) below: 
xe2x80x83in which:
D is a linker arm which represents a linear or branched alkyl chain preferably containing from 1 to 14 carbon atoms, which can be interrupted by one or more hetero atoms such as oxygen, sulphur or nitrogen atoms, and which can be substituted with one or more hydroxyl or C1-C6 alkoxy radicals, and which can bear one or more ketone functions;
the ring members E, G, J, L and M, which may be identical or different, represent a carbon, oxygen, sulphur or nitrogen atom;
n is an integer ranging from 0 to 4;
m is an integer ranging from 0 to 5;
the radicals R, which may be identical or different, represent one of the two valencies of a linker arm B; a second group Z which is identical to or different from the first group Z; a halogen atom; a hydroxyl radical; a C1-C6 alkyl radical; a C1-C6 monohydroxyalkyl radical; a C2-C6 polyhydroxyalkyl radical; a nitro radical; a cyano radical; a cyano(C1-C6)alkyl radical; a C1-C6 alkoxy radical; a tri(C1-C6)alkylsilane(C1-C6)alkyl radical; an amido radical; an aldehydo radical; a carboxyl radical; a (C1-C6)alkylcarbonyl radical; a thio radical; a C1-C6 thioalkyl radical; a C1-C6 alkylthio radical; an amino radical; an amino radical protected with a (C1-C6)alkylcarbonyl, carbamyl or C1-C6 alkylsulphonyl radical; or a group NHRxe2x80x3 or NRxe2x80x3Rxe2x80x2xe2x80x3 in which Rxe2x80x3 and Rxe2x80x2xe2x80x3, which may be identical or different, represent a C1-C6 alkyl radical, a C1-C6 monohydroxyalkyl radical or a C2-C6 polyhydroxyalkyl radical;
R7 represents one of the two valencies of a linker arm B; a C1-C6 alkyl radical; a C1-C6 monohydroxyalkyl radical; a C2-C6 polyhydroxyalkyl radical; a cyano(C1-C6)alkyl radical; a tri(C1-C6)alkylsilane(C1-C6)alkyl radical; a (C1-C6)alkoxy(C1-C6)alkyl radical; a carbamyl-(C1-C6)alkyl radical; a (C1-C6)alkylcarboxy(C1-C6)-alkyl radical; a benzyl radical; or a second group Z which is identical to or different from the first group Z;
R8, R9 and R10, which may be identical or different, represent one of the two valencies of a linker arm B; a C1-C6 alkyl radical; a C1-C6 monohydroxyalkyl radical; a C2-C6 polyhydroxyalkyl radical; a (C1-C6)alkoxy(C1-C6)alkyl radical; a cyano(C1-C6)alkyl radical; an aryl radical; a benzyl radical; a C1-C6 amidoalkyl radical; a tri(C1-C6)alkylsilane(C1-C6)alkyl radical; or a C1-C6 aminoalkyl radical in which the amine is protected with a (C1-C6)alkylcarbonyl, carbamyl or C1-C6 alkylsulphonyl radical; two of the radicals R8, R9 and R10 can together also form, with the nitrogen atom to which they are attached, a saturated 5- or 6-membered carbon-based ring which can contain one or more hetero atoms such as, for example, a pyrrolidine ring, a piperidine ring, a piperazine ring or a morpholine ring, it being possible for the ring to be unsubstituted or substituted with a halogen atom, a hydroxyl radical, a C1-C6 alkyl radical, a C1-C6 monohydroxyalkyl radical, a C2-C6 polyhydroxyalkyl radical, a nitro radical, a cyano radical, a cyano(C1-C6)alkyl radical, a C1-C6 alkoxy radical, a tri(C1-C6)alkylsilane(C1-C6)alkyl radical, an amido radical, an aldehydo radical, a carboxyl radical, a keto(C1-C6)alkyl radical, a thio radical, a C1-C6 thioalkyl radical, a C1-C6 alkylthio radical, an amino radical or an amino radical protected with a (C1-C6)alkylcarbonyl, carbamyl or C1-C6 alkylsulphonyl radical; one of the radicals R8, R9 and R10 can also represent a second group Z which is identical to or different from the first group Z;
R11 represents one of the two valencies of a linker arm B; a C1-C6 alkyl radical; a C1-C6 monohydroxy-alkyl radical; a C2-C6 polyhydroxyalkyl radical; an aryl radical; a benzyl radical; a C1-C6 aminoalkyl radical, a C1-C6 aminoalkyl radical in which the amine is protected with a (C1-C6)alkylcarbonyl, carbamyl or C1-C6 alkylsulphonyl radical; a carboxy(C1-C6)alkyl radical; a cyano(C1-C6)alkyl radical; a carbamyl(C1-C6)alkyl radical; a C1-C6 trifluoroalkyl radical; a tri(C1-C6)alkylsilane-(C1-C6)alkyl radical; a C1-C6 sulphonamidoalkyl radical; a (C1-C6)alkylcarboxy(C1-C6)alkyl radical; a (C1-C6)alkylsulphinyl(C1-C6)alkyl radical; a (C1-C6)alkylsulphonyl(C1-C6)alkyl radical; a (C1-C6)alkylketo(C1-C6)alkyl radical; an Nxe2x80x94(C1-C6)alkylcarbamyl(C1-C6)alkyl radical; or an Nxe2x80x94(C1-C6)alkylsulphonamido(C1-C6)alkyl radical;
x and y are integers equal to 0 or 1; with the following conditions:
in the unsaturated cationic groups of formula (II):
when x=0, the linker arm D is attached to the nitrogen atom,
when x=1, the linker arm D is attached to one of the ring members E, G, J or L,
y can take the value 1 only:
1) when the ring members E, G, J and L simultaneously represent a carbon atom and when the radical R7 is borne by the nitrogen atom of the unsaturated ring; or alternatively
2) when at least one of the ring members E, G, J and L represents a nitrogen atom to which the radical R7 is attached;
in the unsaturated cationic groups of formula (III):
when x=0, the linker arm D is attached to the nitrogen atom,
when x=1, the linker arm D is attached to one of the ring members E, G, J, L or M,
y can take the value 1 only when at least one of the ring members E, G, J, L and M represents a divalent atom and when the radical R7 is borne by the nitrogen atom of the unsaturated ring;
in the cationic groups of formula (IV):
when x=0, then the linker arm D is attached to the nitrogen atom bearing the radicals R8 to R10,
when x=1, then two of the radicals R8 to R10 form, together with the nitrogen atom to which they are attached, a saturated 5- or 6-membered ring as defined above; and the linker arm D is borne by a carbon atom of the saturated ring;
Xxe2x88x92 represents a monovalent or divalent anion and is preferably chosen from a halogen atom such as chlorine, bromine, fluorine or iodine, a hydroxide, a hydrogenosulphate or a C1-C6 alkyl sulphate such as, for example, a methyl sulphate or an ethyl sulphate;
it being understood that the number of cationic groups Z is at least equal to 1.
In formulae (I), (II), (III) and (IV) above the alkyl and alkoxy radicals can be linear or branched.
The compounds of formula (I) can optionally be salified with strong inorganic acids such as HCl, HBr or H2SO4, or with organic acids such as acetic acid, tartaric acid, lactic acid, citric acid or succinic acid.
Among the rings of the unsaturated groups Z of formula (II) above, mention may be made in particular, for example, of pyrrole, imidazole, pyrazole, oxazole, thiazole and triazole rings.
Among the rings of the unsaturated groups Z of formula (III) above, mention may be made in particular, for example, of pyridine, pyrimidine, pyrazine, oxazine and triazine rings.
Among the compounds of formula (I) above which may be mentioned in particular are the compounds of formulae (I)1 to (I)23 below: 
The compounds of formula (I) in accordance with the invention can be obtained easily, according to processes that are generally well known in the prior art, and in particular, for example, by:
condensation of two molecules of a nitrobenzene bearing a haloalkyl radical with one molecule of a compound bearing two tertiary amine radicals separated by a linker arm B as defined in formula (I) described above, or alternatively by
condensation of two molecules of a nitrobenzene bearing a tertiary amine radical with one molecule of a compound bearing two halogen radicals separated by a linker arm B as defined in formula (I) described above, or alternatively
(a) condensation of one molecule of a nitrobenzene bearing a tertiary amine radical with one molecule of a compound bearing two halogen radicals separated by a linker arm B as defined in formula (I) described above, and (b) condensation of a second molecule of a nitro-benzene which is different from the first and which itself also bears a tertiary amine radical, or alternatively
(a) condensation of one molecule of a nitrobenzene bearing a haloalkyl radical with one molecule of a compound bearing two tertiary amine radicals separated by a linker arm B as defined in formula (I) described above, and (b) condensation of a second molecule of a nitrobenzene which is different from the first and which itself also bears a haloalkyl radical, or alternatively
condensation of one molecule of a nitrobenzene bearing a tertiary amine radical with one molecule of a nitrobenzene bearing a haloalkyl radical.
The quaternization step is generally, for convenience, the final step of the synthesis, but can be involved earlier in the sequence of reactions leading to the preparation of the compounds of formula (I).
A subject of the invention is also a composition for dyeing keratin substances, characterized in that it comprises, in a medium which is suitable for dyeing, an effective amount of at least one compound of formula (I) in accordance with the invention.
A subject of the invention is also a compound for the direct dyeing of human keratin fibers such as the hair, characterized in that it comprises, in a medium which is suitable for dyeing, an effective amount of at least one compound of formula (I) in accordance with the invention.
The cationic dibenzenic nitro compound(s) of formula (I) in accordance with the invention and/or the addition salt(s) thereof with an acid preferably represent from 0.005 to 12% by weight approximately relative to the total weight of the dye composition, and even more preferably from 0.05 to 6% by weight approximately relative to this weight.
The compounds of formula (I) in accordance with the invention can also serve in the well-known processes of oxidation dyeing, using oxidation dyes (oxidation dye precursors and optionally couplers), to modify the shade of or enrich with glints the dyeing effects obtained with oxidation dyes.
The dye composition according to the invention can also contain, to broaden the range of shades and obtain varied tints, besides the cationic dibenzenic nitro compounds of formula (I) according to the invention, other direct dyes conventionally used, and in particular nitrobenzene dyes, such as nitrophenylene diamines, nitrodiphenylamines, nitro-anilines, nitrophenyl ethers or nitrophenols, and nitropyridines, anthraquinone dyes, mono- or diazo dyes, triarylmethane dyes, azine dyes, acridine dyes and xanthine dyes, or alternatively metalliferous dyes.
The proportion of all these other additional direct dyes can range from 0.5 to 10% by weight approximately relative to the total weight of the dye composition.
The medium which is suitable for dyeing (or support) generally comprises water or a mixture of water and at least one organic solvent to dissolve the compounds which would not be sufficiently soluble in water. Examples of organic solvents which may be mentioned, for example, are C1-C4 lower alkanols, such as ethanol and isopropanol; glycerol; glycols and glycol ethers such as 2-butoxyethanol, propylene glycol and propylene glycol monomethyl ether; as well as aromatic alcohols such as benzyl alcohol or phenoxyethanol; and similar products and mixtures thereof.
The solvents can be present in proportions preferably ranging from 1 to 40% by weight approximately relative to the total weight of the dye composition, and even more preferably from 5 to 30% by weight approximately.
Fatty amides such as mono- and diethanolamides of acids derived from coconut, of lauric acid or of oleic acid can also be added to the composition according to the invention, at concentrations ranging from about 0.05 to 10% by weight.
Surfactants that are well known in the state of the art and of anionic, cationic, nonionic, amphoteric or zwitterionic type, or mixtures thereof, can also be added to the composition according to the invention, preferably in a proportion ranging from 0.1 to 50% by weight and advantageously from about 1 to 20% by weight relative to the total weight of the composition.
Thickeners can also be used in a proportion ranging from about 0.2 to 5%.
The dye composition can also contain various common adjuvants such as antioxidants, fragrances, sequestering agents, dispersing agents, hair conditioners, preserving agents and opacifiers, as well as any other adjuvant usually used for dyeing keratin substances.
Needless to say, a person skilled in the art will take care to select the optional additional compound(s) mentioned above, such that the advantageous properties intrinsically associated with the dye composition according to the invention are not, or are not substantially, adversely affected by the addition(s) envisaged.
The pH of the dye composition in accordance with the invention is generally from 3 to 12 approximately, and preferably from 5 to 11 approximately. It can be adjusted to the desired value using acidifying or basifying agents commonly used to dye keratin fibers.
Among the acidifying agents which may be mentioned, for example, are inorganic or organic acids such as hydrochloric acid, orthophosphoric acid, sulphuric acid, carboxylic acids such as acetic acid, tartaric acid, citric acid and lactic acid, and sulphonic acids.
Among the basifying agents which can be mentioned, for example, are aqueous ammonia, alkaline carbonates, alkanolamines such as mono-, di- and triethanolamine and derivatives thereof, sodium hydroxide, potassium hydroxide and the compounds of formula (V) below: 
in which W is a propylene residue optionally substituted with a hydroxyl group or a C1-C6 alkyl radical; and R12, R13, R14 and R15, which may be identical or different, represent a hydrogen atom, a C1-C6 alkyl radical or a C1-C6 hydroxyalkyl radical.
The dye composition according to the invention can be in various forms, such as in the form of liquids, creams, gels or any other form which is suitable for dyeing keratin substances, and especially human hair. In particular, it can be packaged under pressure in an aerosol can in the presence of a propellant and form a mousse.
Another subject of the invention relates to a process for dyeing keratin fibers, and in particular human keratin fibers such as the hair, by direct dyeing, which comprises the step of leaving a composition containing at least one cationic dibenzenic nitro compound of formula (I) to act on wet or dry keratin fibers.
The composition according to the invention can be used as a leave-in composition, i.e. after applying the composition to the fibers, they are dried without intermediate rinsing.
In the other application methods, after applying the composition to the fibers for an exposure time ranging from 3 to 60 minutes approximately, preferably from 5 to 45 minutes approximately, the fibers are rinsed, optionally washed, and then rinsed again and dried.